I disagree and will state my reasons below. I think this is a very critical point and not at all a scientific discussion that has no significance in the "real world."
Opposing Arguments and My Thoughts
First of all, the weight groups were described as being "metabolically" healthy or unhealthy. This is typically defined by several factors, including blood pressure, blood sugar, cholesterol, and triglycerides. BMI is calculated by using weight and height. Classifications are shown in the chart below.
Here are the two primary arguments for obesity not being healthy (one from the researchers and one I heard from most people I discussed this with over the past few days):
- The new study shows a higher risk of heart disease or death with healthy obese individuals.
- Obesity wears on joints, leading to knee, lower back, and other pain.
1. Decades of research show that obesity does not consistently demonstrate an increased risk of early death. The National Health and Nutrition Examination Survey (NHANES) is a study that was conducted for several four-to-six-year periods over four decades in the US. After combining all of the data, the researchers found that obese people under 60 years old were 23% less likely to die during the study period when compared to the "healthy" weight group.
2. Obesity assesses total fat, and not all fat is created equal. Inner abdominal fat leads to several negative health consequences, whereas subcutaneous fat (thighs, hips, etc.) produces many benign or healthful actions. This is illustrated by a few points.
First, waist-to-hip ratio, which is essentially a measure of where your fat is stored, is a much more effective way to determine your risk of heart disease when compared to weight. High amounts of abdominal fat often indicate that a person has or will develop diabetes, whereas thigh fat does not indicate anything about diabetes risk. Overall, people who are obese primarily due to excess hip and thigh fat are unlikely to suffer from heart disease or diabetes.
3. Lifestyle is more important than body fat for determining health. Some people are obese but maintain healthy exercise and eating habits. As I pointed out on this blog and in Chapter 3 of my book, lifestyle improvements build health whereas fat removal with no diet/exercise changes (liposuction) does not. When people lose weight while changing their eating/exercise habits, their health improves primarily due to the lifestyle changes, not the fat loss.
This point is critical to make because many people are genetically obese. In some cases, obese people have abnormally high quantities of fat cells. While you can shrink your fat cells through exercise and diet, you cannot decrease the amount of fat cells that you have. Therefore, some obese people have a limit to how lean they can get, and that limit could be in an obese state.
4. Joint pain is largely a matter of strength. I'm not going to tell you that being obese doesn't put extra stress on joints. It does. It's basic physics: when there's more mass, there's more force on the joints. However, I can tell you from experience in my personal training practice, gaining strength decreases or eliminates knee and lower back pain, regardless of weight change. This is supported by research.
Seniors with osteoarthritis in their knees felt huge reductions in pain after a few months of leg strengthening and no weight loss . The same pain reduction was demonstrated in several studies where people performed only one exercise per week to strengthen their lower back. If obese individuals strength train, their knees and lower backs will likely provide little to no pain.
In summary, do I think that obesity is a threat to health? Yes...when body fat is largely located in the midsection. Otherwise, I do not think obesity is a threat to health. Universally, a poor lifestyle is a threat to health. If people - no matter what their weight categories are - regularly practice healthy lifestyle habits, then I think they will maximize longevity while avoiding joint pain, heart disease, and diabetes.